BITS credential problem

Question

I have a service to download file using credential domain\user but get this error :
ErrorCode [-2147023582] 80070522
Description [A required privilege is not held by the client.]
ErrorContext [RemoteFileError]
at Windows Server 2003 64 bits
I'm setting credential so :

                bc.AuthenticationScheme = AuthenticationScheme.Negotiate;
                bc.AuthenticationTarget = AuthenticationTarget.Server;

The user has full access rights on source and destination folders.
Using SharpBits library.

It seems to be missing some right of access yet. Any suggestions?

[EDIT]
It seems that there is some failure in resource access provided by the BITS service.
Still investigating.

[EDIT]
Investigating the rights to use BITS.
-with the command "sc sdshow bits" I get this output on the environment where it works :

D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)
(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)
(A;;CCLCSWLOCRRC;;;AU)(A;;CCLCSWRPWPDTLOCRRC;;;PU)
S:(AU;FA;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;WD)

-where the copy does not work :

D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)
(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)
(A;;CCLCSWLOCRRC;;;IU)(A;;CCLCSWLOCRRC;;;SU)
(A;;CR;;;AU)
(A;;CCLCSWRPWPDTLOCRRC;;;PU)
S:(AU;FA;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;WD)

Answer 1

The solution : added the user "NT AUTHORITY\NETWORK" permissions to read at folders in all remote hosts.
That's it.